Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Health & Balance

Font Size

Why the Sound of Fingernails on a Chalkboard Irks You

Shape of the Human Ear May Amplify Some of the Most Irritating Sounds
WebMD Health News
Reviewed by Laura J. Martin, MD

Nov. 4, 2011 -- The mere thought of fingernails scratching a chalkboard can be enough to set some people on edge.

Now, a new study may help explain why.

Researchers say the shape of the human ear may amplify certain aspects of the sound of fingernails or chalk scraping on a chalkboard to make it even more annoying to the listener.

In addition, people’s perceptions about these irritating sounds may increase stress levels and how they rate the sound.

For example, listeners rated the sounds as more pleasant if they were told they were hearing selections of contemporary music rather than fingernails on a chalkboard.

High Pitches Amplified by Ear Canal

The study shows that fingernails scratching a chalkboard produces sounds at the peak of human hearing, in the frequency range between 2000 and 4000 hertz.

Researchers say the human ear is especially sensitive to sounds within this high-pitch range. One reason is that the anatomy of the ear canal amplifies sounds at these frequencies, making them literally louder to our ears.

When researchers removed pitch information in this range from recordings of fingernails scratching a chalkboard and played them to people, they rated the sounds as more pleasant.

Researcher Michael Oehler, professor of media and music management at the University of Cologne in Germany, says they thought frequencies in the top range of human hearing would play a major role in the unpleasantness of the sounds.

“But we did not know the exact range,” Oehler says in a news release. “The influence of pitch information was greater than we thought.”

Researchers presented the results of their study this week at the annual meeting of the Acoustical Society of America in San Diego.

Some Sounds Have a Bad Rap

The study also suggests that peoples’ perception of sound plays a role in how irritating it is.

Half of the participants were told they were listening to the sound of fingernails or bits of chalk on a chalkboard, and the other half was told they were listening to contemporary music.

The listeners were asked to rate the pleasantness or unpleasantness of the sounds. Meanwhile, researchers measured their stress responses, like blood pressure, heart rate, and sweat.

People who knew they were listening to fingernails on a chalkboard rated the sound as more unpleasant and had a stronger stress response, in particular sweating, than those who thought they were listening to music.

These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.

Today on WebMD

woman in yoga class
6 health benefits of yoga.
beautiful girl lying down of grass
10 relaxation techniques to try.
mature woman with glass of water
Do you really need to drink 8 glasses of water a day?
coffee beans in shape of mug
Get the facts.
Take your medication
Hand appearing to hold the sun
Hungover man
Welcome mat and wellington boots
Woman worn out on couch
Happy and sad faces
Fingertip with string tied in a bow
laughing family